Work-gripping means for well drilling apparatus



Oct. 18, 1932.

F. STONE WORK GRIPPING MEANS FOR WELL DRILLING APPARATUS Filed Jan. 4, 1928 7 Sheets-Sheet 1 J32 002 fo Oct. is, 1932. STONE 1,883,073

WORK GRIPPING MEANS FOR WELL DRILLING APPARATUS Filed Jan. 4, 1928 7 Sheets-Sheet 2 Oct. 18, 1932. F. STONE 1,883,073

WORK GRIPPING MEANS FOR WELL DRILLING. APPARATUS Filed Jan. 4, 1928 7 Sheets-Sheet 5 In we 22 Z07 Frederick $20 26".

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A ZZorney Oct. 18, 1932 STONE 1,883,073-

WORK GRIPPING MEANS FOR WELL DRILLING APPARATUS Filed Jan. 4, 1928 7 Sheets-Sheet 4 F. STONE 1,883,073 WORK GRIPPING MEANS FOR WELL DRILLING APPARATUS Oct. 18, 1932.

Filed Jan, 4, 1928 7 Sheets-Sheet 5 In van/0r Frederik? Sta/2e,

F. STONE Oct. 18, 1932.

WORK GRIPPING MEANS FOR WELL DRILLING APPARATUS 7 Sheets-Sheet 7 Filed Jan. 4, 1928 izy 2/.

172 maze/ 02" .w Rafa/'1 '61: 570/26.

Patented Oct. 18, 1932 UNITED STATES.

PATENT orrlcr.

FREDERICK STONE, OF GLENDALE, CALIFORNIA, ASSIGNOR T DOHENY-STONE DRILL 00., 01 LOS ANGELES, CALIFORNIA, A CORPORATION OF DELAWARE WORK-GRIPIING MEANS FOR WELL DRILLING APPARATUS Application filed January 4,-1928. Serial No. 244,423.

This invention has to do generally with work gripping means for well drilling apparatus and is continuation, in part, of an ap-,

plication entitled Earth boring machines, filed by me January 12, 1924, Serial No. 685,- 744, which has now matured into Patent No. 1,678, 307 and is dated July 24, 1928.

The claims in the above entitled, co-pending application, are drawn to a particular type of drill head mounting, while the claims in the instant case which read on the structure shown in said co-pending application are drawn to the work-engaging or clamping members and their mountings.

At the outset, it is desired to state that while I have shown these work-clamping members and their mountings as applied to a particular type of well drilling apparatus, this is done merely by way of illustration, for it will be readily understood that the invention, considered in its broader aspects, is in no way limited to such specific application. For instance, the work-clamping members may as well be applied to elevators, spiders, standard rotary tables, and the like. However, from an understanding of the typical installation here shown, those skilled in the art will readily see how it may be applied to different apparatus with equal advantage and without departing from the spirit and scope of the appended claims.

It will not be attempted here to discuss exhaustively the various objects and novel features of the invention, for they may be pointed out to much better advantage as the following detailed description progresses. It will suffice to say that the general object of the invention is to provide work clamping members which are adapted to insure proper clamping action under all conditions of use, and also to provide means whereby said mem-. bers may be moved expeditiously and surely to and from operative position, insuring positive gripping with the work when in operative position and full, complete release from the Work when in inoperative position.

The actuating means for accomplishing slip movement is of such a nature that the clamping members or slips may be moved quickly and with but little effort on the part of the operator, the time element of the operation being thus reduced to a' minimum and thereby greatly increasing the efficiency of the apparatus to which the slips are applied. The importance of this time-savin feature is well understood by those skilled in the art and need not be enlarged upon here.

Other novel features and objects of the mvention will be made apparent in the follOWlIlg detailed de-Lcription, reference being had to the accompanying drawings in which:

Fig. 1 is an elevation, partly in bro-kenaway medial section, of a well drilling apparatus to which my invention is applied;

Fig. 2 is a detached, perspective. view of the rotary table of the apparatus;

Fig. 3 is a perspective view of a table bush Fig. 4 is a view table bushing;

Fig. 5 is a perspective view of an embodiment of my improved slips;

Flg. 6 is a perspective View of the slip-liftmg mechanism, certain elements thereof being shown detached from one another;

Fig. 7 is a detached perspective View of an alining thimble for the apparatus;

Fig. 8 is a perspective View of a pair of hold-down plates sometimes used in connection with my apparatus;

Fig. 9 is a front elevation of drilling apparatus to which a variational embodiment of my invention is applied;

Fig. 10 is a side elevation of Fig. 9, parts being broken away to expose enclosed elements;

Fig. 11 is an enlarged, fragmentary view of the upper portion of the table shown in Fig. 10, parts being shown in medial section, and the slip-lifting apparatus being in place;

Fig. 12 is a view generally similar to Fig. 11 except that certain parts shown in section in Fig. 11 are here shown in elevation, and certain parts have been moved to a different position;

Fig. 13 is a top plan view of the table bushing used in connection with the variational form;

3Fig. 14 is a section on line 1414.- of Fig. 1

of a variational type of lii Fig. 19 is a medial section through one ofthe variational slip members, being taken on line 19-19 of Fig. 20;

Fig. 20 is a section on line 20-20 of Fig. 19 but showing additionally the other slip segment in section; Fig. 21 is an enlarged section through the .slip lifting ring and collar;

Fig. 22 is a section on line 22-22 of Fig.

Fig. 23 is a fragmentary top plan view of the table showing hold-down means applied to the slips;

Fig. 24 is a section on line 2424 of Fig.

23; and

Fig. 25 is an enlarged detailed section on line 25-25 of Fig. 23.

As stated above, the present invention may be utilized to advantage in connection with any type of well drilling apparatus whereby vertically extending work, in the form of casing, drill stem or grief pipes, for instance,

is to be gripped, irrespective of whether this grip is applied to impart rotary drive or vertical movement (either up or down) to the work, or where it is merely applied to suspend the work while joint-making or breaking operations are carried out. The nature of these general operations is well understood to those skilled in the art. Accordingly, though I have shown my invention here applied to a particular type of apparatus, it is to be distinctly understood that this showing is in no way to be considered as an inference that the invention or claims are limited to this particular application.

The invention is here shown as embodied in an apparatus which includes a rotary table mounted for vertical reciprocation, there being provided hydraulic means for controlling or forcing upward or downward movement to the table. By virtue of this arrangement work gripped by the means to be hereinafter described may be given rotation, may be lifted or lowered, or may, under certain circumstances, be forced downwardly. Irrespective of the particular operation to be performed upon and by the work, my gripping means and actuating mechanism therefor may be utilized to advantage, but since these operations are well understood by those skilled in the art and are in no way controlling on the present invention, for illustrative purposes I will assume that the work is in the form of a round drill stem which is ada ted to be gripped for rotationor for vertica reciprocation by the supporting body which, in this instance, is a rotary table.

[I have here shown upper and lower frame castings 10 and 11, respectively, which serve espectively as upper and lower heads for by raulic cylinders 12 through which pistons 13 are adapted to be reciprocated or controlled in their vertical movement by the admission of fluid ressure at 14 or 15. Pis- I ton rods 16exten upwardlythrough stufling boxes 17 in head member 10 and carry cross head 18. This cross head supports table 19 for rotation about an axis parallel to and substantiallymidway between piston rods 16.

The particular manner of mounting the table for rotation is in no way controlling on the present invention; in fact, as stated above, it is not essential to the present invention that in all types of apparatus to which my invention may be applied the member equivalent to table 19 be rotatable. Accordingly, I will not describe in detail the mounting of the table (which mounting is the subject-matter of the aforementioned patent), but will merely state that the table has end thrust bearing with the cross head at 20 and 21, and radial bearing therewith at 22 and 23. So also, the means for rotating the table is in no way essential to the present application, it suflicing to say that a driving pinion (not shown) is meshed with the ear teeth 24 provided about the periphery o the table for accomplishin the rotative drive.

By way of explaining the desirability of a certain feature of my gripping assembly it may be stated that as well drilling o erations progress, drill stems of different iameters are used. That is, a relatively large stem is used during initial drilling operations, while a relatively small diameter drill stem is used when the well is deepened, for reasons well understood by those skilled in the art. Accordingly, it is necessary that there be provided gripping elements for the table which will take work of different diameters, and it is, of course, economically desirable that a single table be utilized irrespective of the drill stem diameter. While it is possible to utilize interchangeable slips or gripping members which are of different work-taking diameters though all are adapted to seat in a table socket of given dimensions, the variation in drill stem diameters varies between such widely separated extremes that it becomes often necessary to provide means whereby the size of this slip-taking socket may be changed. To accomplish this, I provide a primary socket within the table which is of a size to take slips which have a capacity to grip work of maximum diameter. Then, instead of utilizing slips having a relatively small work-taking diameter and fitting such slips within said primary socket (it will be seen that such a provision would make the slips of excessive weight, an obviously unde-,

sirable condition), I provide a table bushing which seats within the primary socket, and in turn has a bore or socket adapted to take slips for drill stems of smaller diameter. Thus, in one case, the table itself may be considered as the supporting body for the slips, which body is in direct supporting engagement with said slips, and in the other case the bushing may be considered as the supporting body and as in direct supporting engagement with the slips.

The above rather lengthy explanation is given in order that the terminology of the claims may be understood, for in certain of said claims, the body member there mentioned may be considered as either the table itself or as the bushing.

For the purpose of initial discussion, it will be assumed that a table bushing is used, this bushing being the body member which takes the slips in the following situation. Accordingly, the particular mounting of the bushing within the table need not here be considered, for considering the invention from the present aspectthe bushing mounting is unimportant and need not be the one here shown. It will suffice to say that table bushing 25 is adapted for vertical movement into and out of the axial table bore 26, being held from rotation with respect to the table by virtue of their complementary angularity, as viewed in plan, and limited in its downward movement through the table by reason of the inclination of the outer faces 27 of the bushing, which faces seat upon complementary, inclined faces 28 of the bore defining walls of the table. Of course, any other suit able means may be provided for holding the bushing against rotation and against unlimited downward movementwith relation of the table.

Bushing 25 is preferably made of two separable, symmetrical parts whereby it may be more easily handled, as will be readily understood. The division between the parts may occur either through inclined walls 29 and 30, as shown in Fig. 3, or it may come in the adjacent walls 31 and 32, as in Fig. 4. The latter is preferable, since the faces of walls 29 are pressure-taking faces, as will be hereinafter made evident, and it is therefore desirable that they be unbroken.

Vertically extending work a drill stem, for instance) is adapted to be extended through the bore of bushing 25, and wedge slips or similar work-clamping means generally indicated at 34 are adapted to extend vertically through the bushing bore alongside the 'work to hold said work either or both against rotation and longitudinal movement relative to the bushing.

It is desirable that the movable work-engagement means be made up of a plurality of parts, and it is also preferable that these slip as at 44, and the parts be individually mounted in identical manners and that actuating means be provided whereby they are moved simultaneously. I have shown such conditions existing, but it will be understood that, considering the invention in its broader aspects, it is only essential thatthercbe one such gripping member mounted in the particular manner specified, and that it is not essential that. more than one or that particular one be moved in the manner shown and to be described. Accordingly, certain of my claims contemplate such singularity and the following discussion, where it is assun'aed that all the slips segments are mounted similarly for simultaneous movement, is therefore not to be considered as in any way limiting said claims.

The opposite, inner faces of bushing walls 29, 30, incline inwardly and downwardly toward the axis of the work, and extending inwardly from adjacent faces 36 of the bushing are the central lugs 37 which present at their opposite sides longitudinally extending guide shoulders 38, these shoulders preferably being squire cut and substantially parallel to the inclined faces 35. It will be seen that at each :ide of lug 37 there is thus provided a parallel-sided, square-cut way 39 which inclines inwardly and downwardly toward the axis of the work.

Gripping member 34 is made up of two or more parts 40, each commonly being known as a segmental wedge slip, these parts preferably, though not necessarily, being of like construction. The inner face of each slip is preferably serrated as at 41, or otherwise suitably prepared to furnish a good grip on the work with which it is to contact, the nature of the serration or teeth, preferably, though not necessarily, being such that, when they are in pressural contact with the work, they hold it against relative rotation or longitudinal movement in either direction.

The outer end faces 42 of the slips incline inwardly and downwardly, and, assuming that faces 41 extend vertically or parallel with the work, the angle of incline of a given face 42 is substantially complementary to the angle of incline of an associated bushing face 35. Each slip part also has at each side a shoulder 43 which inclines inwardly and downwardly in substantial parallelism with the face 42 of that slip, and the portion of the slip which extends horizontally between face 42 and shoulder 43 is taken with sliding fit within a corresponding way 39. lVhile this is not essential, shoulder 43 may be formed by cutting back the side, faces of the slip portion 45 thus defined by face 42 and shoulders 43 maybe considered as a parallel-sided, longitudinally extending key which inclines inwardly and downwardly toward the work axis.

It willbe seen that when the slips are entered in the bushing with keys 45 in ways 39,

lit

lVhen the slips are to be released from the work it is necessary that they 'move not only upwardly but also outwardly and, especially where remote control mechanism is depended upon for moving the slips simultaneously, it is important that the slips be given this outward movement in a positive manner. I have provided means for accomplishing this,

which means may also be utilized for press-' ing the slips downwardly and inwardly into engagement with the work, to a certain degree. The means is such that the normal tendency of the parts to bind during operation is effectively overcome. I

In the first place, it will be seen that the engagement of keys 45 in ways 39 forces outward movement of the slips when they are raised and inward movement when they are lowered, it following that it is necessary only to provide means for lowering them and raising them to accomplish inward and outward movement thereof, though the interconnecting means by which this vertical reciprocation is accomplished must be a smooth working and sure one.

For this purpose I have provided a suspension member or ring 46 which encircles work W above the slips, the bore 47 of the ring being of a diameter to take the work nicely so the work, in effect, guides the ring through its vertical reciprocation for movement substantially parallel to the work axis.

Depending from ring 46 are the diametrically opposite lugs 48 which have substantially horizontal offsets 49 extending radially outward therefrom. Ofisets 49, in turn, are provided with transverse slots 50 which incline downwardly and outwardly. Pins 51 extend through these slots and the upright ears 52 of clips 53 which are detachably secured to the tops of the slips by bolts 54. lVith means for supporting ring 46, as will be described, it will be seen that pins 51 serve to suspend the slips from said depending lugs, and it will also be evident that the lower faces 55 of slots 50 provide outwardly and downwardly inclining cam faces upon which the pins 51 are adapted to slide under certain circumstances. When the slips are in operative engagement with the work, as shown in Fig. 1, pins 51 lie near the upper, inner ends of slots 50.

As a means for reciprocating ring 46, I provide a lever 56 which is fulcrumed at 57 to an upright or fulcrum support 58 secured to the non-rotatable cross-head 18 at 59. The

inner end of lever 56 is forked as at 60 to bridge the two-part lifting collar 61, the parts of the collar being bolted together" about the central, reduced section 62 of ring 46, the ring being rotatable, within the collar and being held against vertical movement with respect thereto by reasonof the annular flange portions 63 which extend radially, over the upper and lower faces of the ring. The fork arms 60 have lost motion connection at 64 with collar 61, it following that oscillation of lever 56 causes vertical reciprocation of ring 46, and it will be seen that due to the rotatable mounting of the ring within the collar and the fact that the lever is mounted on a non-rotatable part of the apparatus, the ring may be vertically reciprocated, and with it the slips, whether or not the work be in rotation. The handiness of this feature will be self-apparent to those skilled in the art.

Now it will be seen that slots 50 not only of the lifting ring tends to spread the slips as they rise, and certain of my claims are drawn with that idea in mind.

It may also be mentioned that ring 46 pre sents an upwardly facing, annular shoulder about the work. Assuming that the slips be in inoperative position while. the work is suspended through usual elevators (not shown) and failure of the hoisting apparatus allows the work to drop, the elevators will engage this ring shoulder driving the ring downwardly to set the slips and thus prevent furtherdropping of, the work.

It has been noted that under certain circumstances the slipstaken within the table bushing may not be of suflicient efiective diameter to take work of a required size. By forming the faces of the defining walls of table bore 26 in a manner similar to the inner wall faces of the bushing and providing slips of a size to be taken in the table socket and having the characteristics ascribed to slips 34, these relatively large slips may be inserted directly in the table bore and the same effect of positive radial spread and contraction through vertical reciprocation of the slips may be made. For instance, refer to Fig. 2. It will be seen that the opposite faces 28 of provide a lost motion connection between the the walls defining bore 26 incline inwardly and downwardly, and that central lugs similar to lugs 37, present downwardly and inwardly inclining guide shoulders 66 which extend in parallelism with an opposing face 28. Said faces 28 and shoulders 66 thus define parallel-sided,inwardly inclining ways 67 in walls adj acent thosewhich present faces 28. By then fashioning slips in the manner shown in Fig. 5 but of such dimensions that their corresponding portions fit bore 28 and ways 67, it will be seen that vertical reciprocation of such larger slips is accompanied by simultaneous horizontal movement thereof in the manner described in connection with the smaller slips.

With the table bore thus having inwardly projecting lugs 65, bushing 25 is provided with clearance ways 68 adapted to pass the lugs when thebushing is lowered or raised from the table, these clearance ways being in the walls which carry lugs 37. However, the outer faces of these same walls beyond the clearance way engage the bore defining faces of the table so there may be no loose horizontal movement of the bushing within the table.

It will be. noted by reference to Fig. 1 that the slips stop well short of the bottom of the bushing. Now it is desirable that the work be supported radially or centered with respect to the table as nicely as possible, andto accomplish this it is, of course, desirable that the points of radial support be spread longitudinally along the pipe. For this purpose, I have provided 'a two-part alining or centering thimble 69, each part thereof being made up of a half-sleeve portion 70 and a transverse head flange 71. The sleeve portions embrace the work below the endsof the slips and the thimbles are supported by a keeper or flange 72 bolted at 73 to the lower end of the bushing and extending into the bushing bore sufliciently to underlie the thimble flanges 71.

Under certain circumstances, it is desirable that the work be crowded down, this particularly being the case when the hole is relatively shallow so there is no great amount of drill stem weight applied to the bit and when relatively hard formation is encountered. Under these conditions, it is essential that the bushing and slips be held against movement upwardly with respect to the table, or considered otherwise, it is necessary that the slips and bushings be held crowded down and wedged in work-holding position.

When this is to be done, the slip-lifting apparatus, including clips 53, is removed from the apparatus. Keeper or hold-down plates 74 are then slid across the table beneath the overhanging flanges 74a thereon, the meeting edges of said plates being notched or cut out as at 75 toaccommodate the drill stem. Since flanges 74a hold the plates from movement upwardly. it will be seen that said plates, in turn, hold both the bushings and slips from upward movement'with relation to the table. Furthermore, if it be desired to force the slips downwardly with added pressure, pressure bolts 76 may be. threaded down through the plates into contact with the upper ends of the slip and thus force the latter downwardly into firmfir wedge-tight engagement with the wor So much of the device as has been described in detail was shown in the application which matured into the above mentioned patent.

I will now proceed to describe the variational embodiment of the invention illustrated in Figs. 9 to 25, inclusive.

This variational embodiment is shown applied to an apparatus having the general characteristics of the-structurehereinbefore described, but said structure has certain novel characteristics which are made the subjectmatter of a certain copending application en titled Well drilling apparatus, filed January 4, 1928, Ser. No. 244,422. It may be briefly described as follows: In Figs. 9 and 10, numeral 77 indicates a frame head gen erally similar to member 10 in Fig. 1, this head forming a closure for the upper ends of cylinders 78 which are closed at their opposite ends by lower head 79. Pistons 80 are adapted to be reciprocated or controlled in their reciprocation hydraulically, means for admitting fluid under pressure above or below the piston being designated at 81 and 82, respectively. A non-rotative cross-head 83 is attached to the upper end of piston rods 84 and adapted to be reciprocated thereby,

this cross-head being circular, as viewed in plan, and having an upstanding marginal flange 84a.

The rotary table generally indicated at 86, is mounted for axial rotation within the crosshead in the manner clearly illustrated, the table having 9. depending flange 87 which fits within flange 84a and has internal gear teeth 88 formed thereon. The table is rotated through the medium of a pinion 89 which is in mesh with said gear teeth and is keyed to a vertical shaft 90, said shaft being rotated, in turn. through a gear connection such as a bevel pinion 91 splined on the shaft for vertical movement with respect thereto and driven, in turn, by a bevel pinion 92' carried by shaft 93' which is journaled on frame head 77 as at 94'.

The table is adapted to be vertically reciprocated or controlled in its reciprocation in a manner similar to that described in connection with the mechanism of Fig. 1, and I will now describe the means for drivingly connecting the table to the work either for rotation or vertical movement (up or down) of said work.

Table 86 has a vertically extending, axial bore or socket 92 and an upwardly opening counterbore 93. Dropped into this axial opening is a table bushing generally indicated at 94, the bushing preferably being made up of two similar parts 95. Each part 95 includes a sleeve portion 96, angular, as viewed in plan, and an annular head portion 97. The sleeve portion 96 has external, vertically extending ribs 98 which engage the faces of the bore defining walls 99 of the table to center the bushing sleeve in the bore, while head portion 97 is taken within the counterbore 93. This head portion has radially extending lugs 100 which enter complementary recesses in the table and serve to connect said table and bushing drivingly. Ribs 98 may extend downwardly from head portion 97 to an annular flange 98a provided about the sleeve portion near its lower end and adapted to fit within the table bore.

The lower face 101 of head portion 97 engages the upwardly facing shoulder 102 presented by the table at the junction of its bore and counterbore, the limit of downward movement of the bushing with respect to the table thus being established.

The two halves of the table bushing may be connected as by bolts 980 which extend horizontally between the vertically extending, meeting ribs 98?) on the bushing parts. Preferably, head portion 97 is cored out at intervals to provide segmental recesses 103, a particular recess 103a being utilized to contain a locking pin hereinafter described, said pin and its actuating mechanism thus being housed by the defining walls of said recess, to obvious advantage.

Thus, I have shown in recess 103a a horizontally reciprocable locking pin 104 which extends radially through the alinedopenings 105 and 106 in the vertical walls defining said recess. A vertical stub shaft 107 (see Fig. 14) extends across the recess and is journaled, as at 108, in the upper and lower defining walls thereof, the upper end of said shaft being presented at the top of the table and having a socket 109 (Fig. 13) to take a rotating or wrenching tool. The vertical shaft carries a pinion 110 in mesh with the rack teeth 113 on locking pin 104, and it will be seen that rotation of said vertical shaft through the application of asuitable tool serves through the pinion and rack to T6011).- rocate the locking pin horizontally.

Before the bushing is inserted in the table, the inion is actuated to draw pin 104 inwar ly until its outer end is flush with the peripheral face of the head portion. The bushing is then dropped into place with pin 104 in register with a horizontal bore 114 in table 86, said here opening to countcrbore 93. The vertical shaft is then actuated to project the locking pin into table pocket 114, said pin thereafter releasably holding the bushing against movement upwardly with respect to the table.

The faces 115 of opposite walls 116 (which, with adjacent walls 117, define the angular,

vertically extending bore or openin 118 of bushing 94) incline inwardly and downwardly toward the axis of work'W, and central lugs 117a provided on walls 117 (the equivalents of lugs 37 in Fig. 3), present guide shoulders 119 which oppose and parallel inclined faces 115. These inclined faces and guide shoulders thus define the parallel sided ways 120 which incline inwardly and downwardly as do the Ways 39. At their lower ends 115a, walls 116 and 117 may extend parallel to the work axis as shown, to provlde a clearance recess R about the work where it extends below the slips.

The slips are shown in detail in Figs. 16, 19 and 20, the two-part clamping assembly being indicated at 121, the two parts 122 being similar. Each part has an outer face 123 which inclines inwardly and downwardly complementarily to a given face 117, the two inclined faces 123 befng opposite the arcuate faces 124 which are adapted to encircle work W and to engage the work grippingly, either directly or indirectly. In the illustrated embodiment, though this is not limitative on the invention, considered broadly, the actual engaging or pipe gripping members are in the form of inserts 125 reniovably carried by the slip bodies and projecting inwardly from faces 124. The preferred means for retaining these inserts within their carriers or slip bodies will be discussed at a later point in the specification.

The slip parts 122 are cut in on the walls adjacent the inclined wall as at 126 to provide oppositely extending key portions 127, the inner faces 128 thereof being parallel to faces 123. The face 123 and face or shoulder 128 on a given slip part thus define a parallel-sided, downwardly and inwardly inclining key which is adapted to have sliding fit within way 120, and it will be seen that the coaction of these key portions on the slip parts with the defining walls of the ways causes the horizontally inward and outward movement of the slips during vertical movement thereof in a manner similar to that described in connection with the slips used in the device of Fig. 1. It will be unnecessary to repeat here the purposes and advantages of this horizontal translation.

I will now describe the type of means here employed for vertically reciprocating or controlling the reciprocation of the slips. It may be here noted that this reciprocating or controlling means is generally similar to that previously described, but has as one feature of difference and advantage, 11u1ncly,'the utilization of two-point suspension means for each slip element, balance thereby being preserved and smooth action insured. The top of each slip has a pair of threaded apertures 129 adapted to receive the threaded shanks 130 ofupwardly opening clevises 131. These clevises carry across their mouths horizontal pins 132 which extend through downwardly and outwardly inclining slots 133 provided in lugs 134, the latter depending from lifting ring 135 and extending between the arms of the clevises. Ring 1215 encircles work 1V, being reciprocable vertically therealong and being guided in its reciprocation by the work so it moves substantially parallel to the work axis.

A two-part lifting collar 136 is mounted within the annular groove 137 ofthe lifting ring, said collar and ring being relatively rotatable, and there preferably being provided a transverse opening 137a (Fig. 17) through one of the parts of collar 136 whereby lubricants may be introduced between the bearing faces of the ring and collar.

Collar 136 carries outwardly extending, diametrically opposed studs or pins 138 which are adapted to be taken within the slots 139 provided at the ends of fork arms 140 of lever 141, said fork arms extending about the ring and collar. Lever 141 has transverse lugs 142 which are removably entered in the upwardly opening slots 143 in fulcrum arm 144, the fulcrum arm being detachably held to the upstanding flange 84a of the non-rotatable cross-head through a bracket 147 bolted to said flange at 148. For instance, said bracket may have upwardly opening and downwardly inclining grooves or ways 149 into which the complementary lugs 150 on arm 144 are adapted to be entered from above.

Lever 140 is thus mounted for oscillation about point 142, such oscillation acting through the lost motion connection 138, 139, to elevate, depress, or control the depression of the collar and ring and hence of the slips. It will be seen that this slip-lifting or controlling assembly has every essential characteristic of that described in connection with the showing of Fig. 1, and it therefore follows that the slip movement and advantages derived therefrom described in connection with- Fig. 1 are also true of this varlational embodiment, and therefore need not be repeated here.

As a member equivalent to and functioning as thimble 69, I have provided a two-part alining or centering member 151 (Figs. 12 and 15a). This member is made up of the two similar parts 152 which, together. define a bore 153 adapted to take the work 1V at a point spaced below the bottom of the slips. Member 151 has upper and lower vertically spaced flanges 154 which engage the opposite sides of the angular, horizontally extending flange 155 provided on the lower end of the master bushing, the halves of the alining member being horizontally slipped into place before assembly of the master bushing and being detachably secured thereto by bolts 155a, though this belt securement is not essential since the thimble halves cannot be dislodged without removing and separating the bushing halves. Preferably, the member is relieved at its upper and lower sides as at 156 for obvious reasons.

While it lies within the scope of the invention considered in its broader aspects, to provide any suitable type of work engaging faces for the slips, I have here shown and will describe a preferred assembly wherein the slip bodies act as carriers for readily removable inserts which, in turn, have spectally. prepared surfaces for grippingly en gaging the work. The general advantage of this assembly will be self-evident, for it will be readily understood that the carriers or slips bodies maybe made of cast material and therefore relatively cheap, while the ac tual work-engaging members may be made of specially treated material of a more expensive nature and, when they become unduly worn, may be replaced without the necessity of furnishing an entirely new slip body. Furthermore, while these inserts may have gripping teeth which are well adapted to engage the work either for thrusting it down or lifting it, in certain situations it is desirable that the teeth be fashioned so they are particularly efficient either for the uplifting or down-pressing of the work. Then, when occasion arises for a reverse operation on the work, the inserts may be easily removed, turned end for end, and reinserted in the carriers. of bodies.

Thus, I have shown in Figs. 19 and 20 upper and lower annular grooves 157 and 158, respectively, sunk in the inner arcuate faces 159 of the slips, to which grooves, the upper and lower ends of the vertically ex tending channels or grip-receiving recesses 160 open.

The downwardly; facing shoulder 161 of flange 161?) which defines the top of groove 157 inclines inwardly and downwardly, oven hanging the complementarily formed ends 162 of the slip inserts or grips 163, said inserts being positioned within the channels or pockets 160 and having their inner faces serrated or otherwise suit-ably formed at 164 for gripping engagement with the work. The inserts are dropped into the pockets 160 and moved upwardly until their upper ends are overhung by faces 161, said upper ends thus being held from inward displacement by the correspondingly inclined and mutually engaging walls 161 and 162. Half retainers or keepers 165 are then inserted in the lower grooves 158, these rings having upwardly and inwardly inclining faces 166 which engage complementarily formed faces 167 at the lower ends of the inserts. The rings are then detachably secured to the slip bodies by such means asv bolts 168 (Fig. 20), the opposed, angular faces 161 and 166 partially overlapping, respectively, the upper and lower ends of the inserts longitudinally or vertically so as to hold said inserts against inward displacement. It will be seen that bolts 168 exert on retainers 165 a force directed toward the slip bodies.

When occasion arises for replacing or reversing the inserts, it is merely necessary to remove bolts 168, insert suitable tools in the bores 169 which open at opposite ends to grooves 158 and the outer faces of the bushing, and tap said tools against the rings in a manner to dislodge them from their grooves. Thercupon, the inserts may be drawn down to release their ends from the upper overhang of the slip body and pulled from the pockets.

Furthermore, when a given set of inserts becomes unduly worn, the inserts may be removed, resharpened and replaced in the pockets, being backed by shims 161a placed within said pockets, true circumferential engagement of the insert set with the work thus being preserved.

As described in connection with the apparatus shown in Fig. 1, occasion sometimes arises for crowding the work down, or, expressed otherwise, exerting a down-thrust on the work through a positive down-forcing of the table. As explained above, this requires that the bushing and slips be held positively from movement upwardly with respect to the table, and usually an additional force tending to crowd the slips into wedging engagement with the work. The locking pin 104 sufiices to hold the bushing from movement upwardly with relation to the table, but there is still necessity for means to hold the slips down in the bushing or for crowding them down. I have devised an effective and simple arrangement for accomplishing this. This means is shown in detail in Figs. 23 and 25, inclusive. Before this means is employed, however, the slip lifting mechanism is disassembled, this operation being an easy and quick one. For instance, the oscillatory lever 141 is merely lifted clear of the fulcrum arm through slot 143, at the same time clearing the forked end of said lever from the pins on the lifting ring; thefulcrum arm is slipped upwardly out of the bracket way, and clevises 131 are unscrewed from the bushings.

A bridge or jack bar 170 is then assembled with the bushing. There is a bridge for each sleeve, each bridge embodying a cross bar 171 having depending legs 172 from which extend hooks or transverse extensions 173. The top of the table bushing 15 provided with slots 174 which open to underlying recesses 103. The bridge is moved into position by laying it on top of the bushing with hooks 17 3 extending through slots 174 and then rotatin the bridge as indicated by dotted lines in ig. 25 to bring hooks 173 beneath the underside of the upper bushing wall. The central ack screw 175 is then threaded down through the bridge and into end engagement with the top of the respective slip, the upwardly facing shoulders 176 of the hook ends being thus drawn tightly against the underside of the bushing top, and the slips being crowded down and thus inwardly into tight engagement with the work.

It will be understood the drawings and description are to be considered merely as illustrative of and not restrictive on the broader claims appended hereto, for various changes in design, structure and arrangements may be made without departing from the spirit and scope of said claims.

I claim:

1. In a device of the character described, a body member havin a vertically extending bore adapted to take vertically extending work, one of the wall-defining faces of the bore being inclined inwardly and downwardly, a bushing movable vertically into and out of said bore and having a bore therein and having an outer face inclining inwardly and downwardly and adapted to seat on said inclined face of the body member bore, said body member and bushing having coacting means holding them from relative rotation, one of the defining faces of the bore in said bushing being inclined inwardly and downwardly, an inclined guide shoulder on a wall face of the bore in said bushing adjacent to said last mentioned inclined face, said last mentioned inclined shoulder being opposed and substantially parallel to said last mentioned inclined face, and a work clamping member adapted to move vertically in said bore of the bushing with a portion thereof confined between said last mentioned inclined face and opposed inclined shoulder.

2. In a device of the character described, a body member having a vertically extending bore adapted to take vertically extending work, one of the wall-defining faces of the bore being inclined inwardly and downwardly, an inclined guide shoulder on a wall face adjacent to the inclined face, said shoulder being opposed and substant ally parallel to said inclined face, a work clamping member adapted to move vertically in said bore with a portion thereof confined between said inclined face and said opposed inclined shoulder, and means for moving said clamping member vertically through the bore and embodying a suspension member mounted above the clamping member for movement parallel to the axis of the work, a pin and slot connection suspending the clamping member from the suspension member, the slot of the connection inclining downwardly and outwardly with relation to the work, and means for vertically reciprocating said suspension member.

3. In a device of the character described, a body member having a vertically extending bore adapted to take vertically extending work, one of the wall-defining faces of the bore being inclined inwardly and downwardly, an inclined guide shoulder on a wall face adjacent to the inclined face, said shoul der being opposed and substantially parallel to said inclined face, a work clamping member adapted to move vertically in said bore with a portion thereof confined between said inclined face and said opposed inclined shoulder, and means for moving said clamping member vertically through the bore and embodying a suspension member mounted above the clamping member for vertical reciprocation and guided by the work through a path substantially parallel to the work axis, a pin and slot connection suspending the clamping member from the suspension member, the slot of the connection inclining downwardly and outwardly with relation to the work, and means for vertically reciprocating said suspension member.

4. In a device of the character described, a body member having a vertically extending bore adapted to take vertically extending work, a pair of opposite wall defining faces of the bore being inclined inwardly and downwardly, a pair of guide shoulders on wall faces adjacent to the inclined faces, each of said shoulders being opposed and substantially parallel to an associated inclined face, a pair of work clamping members adapted to move vertically in said bore and having portions confined, one each, between one of said inclined faces and the associated inclined shoulder, and means for simultaneously moving said clamping members vertically through the bore, said means embodying a suspension member mounted above the clamping members for movement parallel to the axis of the work, pin and slot connections suspending the clamping members individually from the suspension member, the slots of the connections each inclining downwardly and outwardly with relation to the work, and means for vertically reciprocating said sus pension member.

5. In a device of the character described, a body member having a vertically extending bore adapted to take vertically extending work, a work clamping member adapted to be moved upwardly and downwardly through said bore alongside the Work, and means for so moving the clamping member and embodying a suspension member mounted above the clamping member for movement parallel to axis of the work, an upwardly presented cam face on said member inclining downwardly and outwardly from the work axis, and a suspension element on the clamping member engaging said cam face to suspend the clamping member from the suspension member and adapted to ride along said cam face during upward movement of the carrier.

suspension member, and means for vertically reciprocating the suspension member.

6. In a device of the character described, a body member having a vertically extending bore adapted to take vertically extending work, a plurality of work-clamping members adapted to be moved upwardly and downwardly through said bore alongside the work, and means for so moving the clamping members simultaneously and embodying a ring surrounding the work above the clamping member and being vertically reciprocatable along the work, lugs on the ring and having slots inclining downwardly and outwardly from. the work axis, and pins carried in said slots and suspending said clamp members individually from the ring.

7. In a device of the character described, a body member having a vertically extending bore, a bushing movable vertically into and out of said bore, wedge slips in the bushing bore and adapted to support vertically ex tending work in horizontally spaced relation to the bushing walls, and a work-centerin thimble applied to the lower end of the bushing and extending horizontally inwardly into engagement with the work below the slips.

8. In a device of the character described, a plurality of segmental wedge slip bodies defining a vertically extending, work-taking bore, one of said bodies having a vertically extending pocket opening at one side to the bore-defining face, a removable work-grip ping element in said pocket, a portion of the body vertically overlapping one end of the element to hold said end in the pocket, and a ring segment detachably secured to the body and having a portion vertically overlapping the other end of the element to hold it in the pocket.

9. In a device of the character described, a vertically extending work-gripping element carrier, a removable work gripping element applied to the carrier, horizontally spaced shoulders on the carrier engaging opposite sides of the element, means on the carrier vertically overlapping one end of the element to hold said end to the carrier, and a keeper detachably secured to the carrier and having a portion vertically overlapping the other end of the element to hold it to the 10. In a device of the character described, a body member havin a vertically extending bore adapted to ta (e vertically extending work, a work clamping member adapted to be moved upwardly and downwardly through said bore alongside the work, coacting means on the body member and clamping member to move said clampingmember horizontally towards and away from the work axis as said clamping member is moved vertically; and means for moving the clamping member vertically, said last mentioned means embodying a suspension member mounted above the clamping member for movement parallel to the axis of the work, a in and slot connection suspending the c amping member from the suspension member, the slot of the connection inclining downwardly and inwardly with relation to the work, and means for vertically moving said suspension member.

11. A device of the class described, comprising a slip having a face shaped to define a portion of a work receiving passage, said slip having a recess extending inwardly from said face; an insert in said recess and means for retaining said insert therein; said means comprising mutually engaging walls, at one end of the device, on the slip and on the insert and correspondingly inclined to retain the insert in position, a retaining member, at the other end of the device, having an inclined portion engaging a correspondingly inclined wall on the insert and means for exerting on said retaining member a force directed toward the body of the slip.

12. A slip for gripping jaws having a gripreceiving recess, a grip in said recess and a grip plate secured to one end of the slip for retaining the grip in position, the end of the plate and grip having cooperating inclined surfaces whereby upon tightening the plate the grip shall be clamped both longitudinally and laterally against the slip.

13. A slip for gripping jaws having a flange, a grip received within said slip and resting against said flange, and a grip plate secured to said slip, the end of the plate and grip having cooperating inclined surfaces whereby upon tightening the plate the grip shall be clamped longitudinally against the flange and laterally against the face of the slip.

14. A slip for gripping jaws having a gripreceiving recess, a grip 1n said recess and a a grip plate secured to the slip for retaining the grip in position, the end of the plate and grip having cooperating inclined surfaces whereby upon tightening the plate the grip shall be clamped both longitudinally and laterally against the slip.

In witness that I claim the foregoing I have hereunto subscribed my namethis 31st day of December, 1927.

FREDERICK STONE. 

